Pavement cutting machines, commonly also known as road routers, are used to open and clean random cracks that have formed in the pavement due to curing irregularities, wear and tear, weathering, and freezing of the pavement. Pavement cutting machines all have in common a frame and a generally circular cutting wheel carried by the frame that rotates during operation and is brought into engagement with the pavement to cut the pavement, preferably as close to the crack as possible, to thereby clean and open the crack. Once cleaned and opened, a sealant, such as tar, bitumen or asphalt is applied to fill the crack to make it relatively level while helping to prevent further cracking and deterioration of the pavement.
The cutting wheel typically consists of a relatively massive disk having a plurality of cutting elements circumferentially spaced around the wheel. During operation, it is the cutting elements that contact the pavement to abrade and thereby cut the pavement to remove the pavement to clean and open the crack. Since the pavement is typically constructed of a relatively hard material, such as concrete, brick, asphalt or another similar material, the individual cutting elements wear and must periodically be replaced.
To replace a cutting element, the pavement cutting machine must be tipped about its wheels to lift the cutting wheel sufficiently far off the ground so that the cutting wheel can be easily accessed. Unfortunately, this is no easy task because pavement cutting machines typically weigh several hundred pounds and are rather unwieldy.
In one known commercially available road router pavement cutting machine, the Cimline PCR-25 manufactured by Cimline, Inc., of Minneapolis, Minn., to access the cutting wheel the machine must first be tipped forwardly about its wheels until it bears against a bracket attached to the front end of the frame and thereafter a skid plate must be partially removed from the rear of the frame. As a result of needing to remove the skid plate to access the cutting wheel, removing any part of the cutting wheel, including replacing any of its cutting elements, is a rather time consuming job. The reason why the skid plate must be removed is because the Cimline machine cannot be tipped from its generally upright operating position far enough forwardly about the axes of its wheels.
What is needed is a stand for a pavement cutting machine that permits the machine to be tipped far enough about at least one of its wheels to expose its cutting wheel sufficiently so that the cutting wheel can be accessed and serviced without requiring the skid plate of the machine to be even partially removed.
During operation of a pavement cutting machine, it is often necessary for its operator to walk away from the machine to attend to some other matter. Unfortunately, if the engine is left running while unattended, the cutting wheel also rotates because it is coupled to the engine by a belt. Should any portion of the cutting wheel come into contact with the ground while left unattended, the machine can be self-propelled by the cutting wheel which can possibly injure someone nearby or damage the pavement cutting machine should it crash into another object.
To remedy this problem, most, if not virtually all, pavement cutting machine manufacturers have an engine kill switch that when released shuts off the engine stopping the cutting wheel. However, it is certainly undesirable to be constantly starting and stopping the engine each time the operator wishes to leave the pavement cutting machine unattended, even if for only a few moments. The more frequent starting and stopping of the engine wastes fuel and increases engine wear. And it can also undesirably increase the amount of time needed to finish the pavement cutting job sought to be done.
Although it is known to use a clutch mechanism in combination with a deadman's switch to selectively stop and start a cutting blade of a lawnmower while allowing its engine to keep running whether or not the blade is disengaged, it is not heretofore known to use a clutch mechanism to selectively control operation of the rather massive cutting wheel of a pavement cutting machine. These cutting wheels typically weigh fifty pounds or more and up until now it was thought impossible to selectively couple and decouple them to an engine without harming the engine, the clutch or both.
What is needed is a clutch mechanism for selectively coupling and decoupling a cutting wheel of a pavement cutting machine for enabling a pavement cutting machine to be left unattended while not needing to stop its engine.